Changing an Activity that has been assigned

Summary

Activity updated after being assigned - will it flow through and change the activity for employees?

Content

Total issue:  

• We assigned a bundle that contained 3 activities
• One of the activities was an Employee PDF form - but the form we tied to the activity was the wrong one
• To correct this, we changed the activity so the right form is now associated with it.
• The activity name didn't change - just the form

For the employees who have not yet completed this activity...but had it assigned before the correction was made....will the correction automatically flow down?  Or because the activity was assigned when the wrong form was tied to it...will the wrong form still show when the employee goes to complete that activity?